1. Field of the Invention
The present invention relates to a scanning laser microscope for observing a sample image illuminated with laser light. In particular, the present invention relates to a scanning laser microscope that can accurately monitor the power of laser light from a light source.
This application is based on Japanese Patent Application No. 2005-172144, the content of which is incorporated herein by reference.
2. Description of Related Art
A known laser microscope includes a light source that emits laser light having multiple wavelengths that are different from each other, an illumination optical system that irradiates a sample with the multi-wavelength laser light from the light source through an objective lens, an observation optical system that receives light emitted from the sample by irradiation of the multi-wavelength laser light to obtain a sample image, a beamsplitting unit that splits off part of the multi-wavelength laser light as reference light before the sample is irradiated with that light, a wavelength-selecting unit that selects a light component having a predetermined wavelength from the reference light split off by the beamsplitting unit, and an intensity-detecting unit that detects the intensity of the light component having the predetermined wavelength selected by the wavelength-selecting unit (for example, see Japanese Unexamined Patent Application Publication No. 11-174332).
Another known laser microscope includes a light source that emits laser light, a scanning unit that scans the laser light onto a sample, a photodetector that detects light from the sample, a processing unit that converts a signal from the photodetector into an image signal of the sample and that outputs the image signal, a reference light detector that detects part of the laser light emitted from the light source as reference light, a correction data processing unit that converts a signal from the reference light detector into correction data corresponding to the position on the sample illuminated with the laser light and that outputs the correction data, and a correcting device that corrects the image signal of the sample output from the processing unit on the basis of the correction data output from the correction data processing unit (for example, see Japanese Unexamined Patent Application Publication No. 2004-219513).
In the laser microscope disclosed in Japanese Unexamined Patent Application Publication No. 11-174332, the wavelength selection is performed using a turret plate including a plurality of bandpass filters provided on the side of the reference light or using an acousto-optical tunable filter (AOTF), and the light intensity is monitored.
The laser microscope disclosed in Japanese Unexamined Patent Application Publication No. 2004-219513 is designed so that even when the intensity of the laser light varies in detecting the reference light, the resulting image is not affected by the variation.